In a Superflat world in a village I built some houses adn iron golems, after a night when the mobs where gone but a iron golem was swinging its arms and attacking nothing, it was as if there was a zombie there because he was staying in the same place. he was staying at a little villager farm and it looked kinda like he was trying to attack the carrots or somthing!
Steps to Reproduce:
1. ... I have no clue how to make this happen